Power supplies used in some applications, for example, an array of battery cells used in an electric or hybrid electric vehicle (HEV), have retention and load carrying requirements that must be met. In particular, an HEV battery pack needs to be retained in six linear directions, and at the same time is limited to a maximum load carrying capability. It is therefore desirable to have a structure that is easy to assemble and capable of transferring or carrying loads that would otherwise be felt by the battery cells.